1. Field of the Invention
The present invention in general relates to the field of biotransformation of furanic compounds. Such biotransformations find utility in the production of furan-2,5-dicarboxylic acid (FDCA) and processing of lignocellulose containing material e.g. for the production of biofuels and biochemicals. More particular the present invention relates to novel genetically modified cells with improved characteristics for biocatalytic transformation of furanic compounds. A further aspect of the invention relates to a vector suitable for genetic modification of a host cell to improve its characteristics for biotransformation of furanic compounds. Other aspects of the invention relate to processes for biotransformation of 5-(hydroxymethyl)furan-2-carboxylic acid (HMF-acid) and its precursors with the use of the cell according to the invention.
2. Description of Related Art
Biotransformation of furanic compounds is receiving increasing attention. This is both in respect of the bioproduction of furan-2,5-dicarboxylic acid (FDCA), which is a promising value added chemical from biomass (Werpy et al. (2004)), and in respect of their negative role in the fermentative production of biofuels and biochemicals from lignocellulose containing materials (Almeida et al. (2009)).
Recently a furanic compound utilising organism, Cupriavidus basilensis HMF14, has been isolated (Koopman et al. (2010a). This organism is capable of metabolizing furfural and 5-(hydroxymethyl)furan-2-carbaldehyde (HMF). The furfural and HMF degradation pathway of Cupriavidus basilensis HMF14 has been disclosed by Koopman et al. (2010a) together with the genes involved.
The functional introduction of the hmfH gene from Cupriavidus basilensis HMF14 in Pseudomonas putida S12 is disclosed by Koopman et al. (2010b). The resulting strain has good FDCA production capabilities using HMF as a substrate. However, the observed accumulation of 5-(hydroxymethyl)furan-2-carboxylic acid (HMF-acid) would require long process times or alternative measures to remove this by-product. Sufficient removal of the HMF-acid by-product is desirable for many of the applications for which the FDCA may be produced and sometimes even is essential.
In search of a solution of the problem of HMF-acid accumulation, the inventors of the present invention have now surprisingly found that expression of certain polypeptides in the Pseudomonas putida S12 FDCA production system, effectively reduces HMF-acid accumulation.